This invention relates to control devices for use with television receivers, in particular remote control devices responsive to illumination by a light beam for controlling the audio output and electrical power input to a television receiver.
In viewing and listening to a television receiver it is often desirable to mute the sound thereof during interruptions. A particularly annoying interruption generated by the television itself is the commercial time-out during which the programming is temporarily stopped and replaced with one or more advertisements. Typically these commercials are of little interest to the viewer and are often noisy; thus it is useful to be able to mute the television's audio output during these commercials in order to enable persons in the viewing room to carry on a conversation. In addition, a television viewer is frequently interrupted by telephone calls and conversations with other persons during which it would be convenient to mute the sound of a nearby television.
It is also desirable to be able to mute the television by remote control, since television commercials occur frequently enough that it would be a greater annoyance than the sound to walk over to the television every time a commercial is broadcast, and since the ability of the viewer to mute the television from the viewing position would save the viewer time in answering a telephone or carrying on other activities during a commercial break.
While it is desirable to be able to mute the audio output of a television during interruptions, such action produces a problem in that when the viewer leaves his viewing position to pursue some other task he can easily forget about the television and not return to turn it off because the sound no longer reminds him that the television is on. Of course the viewer will eventually return to use the television or turn it off, but in the interim the remaining lives of the parts of the television have been needlessly reduced and valuable electrical energy has been wasted. Therefore it would be extremely desirable to provide such a remote control device which disables the television by automatically turning it off a predetermined time following its muting unless the viewer restores the audio to a listening level.
Other devices have previously been designed for controlling the audio output and power of a television receiver from the remote position of the viewer. For example, Polley U.S. Pat. No. 2,903,575 shows a primarily electronic device responsive to the illumination of a light beam for, among other things, turning a television receiver on and off and varying the amplitude of its audio output. However, it is particularly significant that the Polley control system makes no provision for automatically disabling the television if the audio is not restored to a listening level following its muting.